This application claims the benefit of Korean Application No. 2000-55200, filed on Sep. 20, 2000, in the Korean Industrial Property Office, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to an optical scanning apparatus, and more particularly, to an optical scanning apparatus for scanning using a beam scattered by a bubble which moves at a predetermined speed within a fluid pipe.
2. Description of the Related Art
Optical scanning apparatuses are employed in printers and emit, for example, laser beams to scan a photosensitive medium, such as a photoreceptor belt, to form an electrostatic latent image. In particular, as demand for color printing increases, interest in employing scanning apparatuses in color printers has increased. Color laser printers typically include scanning apparatuses for four colors, i.e., yellow (Y), magenta (M), cyan (C) and black (BK), respectively.
Referring to FIG. 1, a conventional optical scanning apparatus includes a light source 100, a rotary polygon mirror 105 rotated by a motor (not shown) for reflecting light emitted from the light source 100, an f-xcex8 lens 115 for allowing the light reflected by the rotary polygon mirror 105 to form appropriate spots on a scanning line 118 of a photosensitive medium, for example, a photoreceptor belt 110, and a reflecting mirror 120 disposed on an optical path between the f-xcex8 lens 115 and the photoreceptor belt 110, for reflecting incident light so that the path of the light transmitted by the f-xcex8 lens 115 is directed toward the scanning line 118 on the photoreceptor belt 110. A predetermined electrostatic latent image is formed on the photoreceptor belt 110 by turning the light source 100 on and off.
Meanwhile, a collimating lens 122 for converting incident light into parallel light and a cylindrical lens 135 for forming a linear image on the reflecting surface of the rotary polygon mirror 105 are disposed on the optical path between the light source 100 and the rotary polygon mirror 105. Reference numeral 125 denotes a sensor for detecting the position at which the scanning line 118 begins.
Here, light emitted from the light source 100 is converted into parallel light by the collimating lens 122. The parallel light is transmitted by the cylindrical lens 135 and then reflected by the rotary polygon mirror 105. The light reflected by the rotary polygon mirror 105 is transmitted by the f-xcex8 lens 115 and redirected by the reflecting mirror 120 so that a spot is formed at a certain portion on the scanning line 118 of the photoreceptor belt 110.
As described above, a conventional optical scanning apparatus including the f-xcex8 lens 115 and the rotary polygon mirror 105 has a complex structure and is quite large. In addition, f-xcex8 lenses are mostly aspheric so that it is very difficult to manufacture the lenses and the lenses are very expensive. Since it is difficult to manufacture, the percentage of defects of products is high. This brings about a drop in color registration performance.
To solve the above problems, it is an objective of the present invention to provide an optical scanning apparatus in which a bubble circulates in a closed loop fluid pipe at a constant speed and in which scanning is performed using a beam scattered by the bubble, thereby reducing volume, facilitating manufacturing and decreasing manufacturing costs.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Accordingly, to achieve the above and other object of the invention, there is provided an optical scanning apparatus including a light source for emitting light; a closed loop fluid pipe; a fluid contained in the fluid pipe, transmitting the light emitted from the light source; at least one bubble contained in the fluid pipe, scattering the light emitted by the light source; a pump installed at one side of the fluid pipe, circulating the bubble at a predetermined speed; and an image formation lens focusing the light emitted by the light source and scattered by the at least one bubble to form an image on a predetermined scanning line.